San Tan Valley weather in December

In December, San Tan Valley sees average daytime highs of 65°F and overnight lows near 43°F, with 1.3 in of rain across 4.3 wet days and about 9.8 hours of daylight. It is the 12th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 67°F in the first days to 63°F by the end. The sky is clear or mostly clear about 58% of the time in December, and the air most often feels dry.

Daylight stretches from about 10 hours at the start of December to 9 h 48 min by month's end. Set against the rest of the year, December is San Tan Valley's 10th-clearest and 9th-windiest month. For the whole year in context, see San Tan Valley's year-round climate.

Daytime high: 65°; 12th warmest
Overnight low: 43°; 2nd coldest
Rainfall: 1.3 in; 4.3 wet days
Daylight: 9 h 48 min; 7:28 AM – 5:17 PM
Cloud cover: 37%; 10th clearest
Wind: 5 mph; 9th windiest
Solar energy: 3.19 kWh/m²
Travel score: 7.0; out of 10

San Tan Valley is unincorporated community in Pinal County, Arizona, United States of America.

Founded: 2009

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

← November San Tan Valley year-round climate January →Best places to visit in December

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 67°F in the first days to 63°F by the end.

A typical December day in San Tan Valley reaches about 65°F in the afternoon and slips back to 43°F overnight — a 22°F spread between the day's warmth and the night's chill. On most days the high lands between 55°F and 73°F. Set against its neighbours, December runs about 10°F cooler than November and on par with January.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°F)	68	68	67	67	67	66	66	66	66	65	65	65	65	64	64	64	64	64	64	63	63	63	63	63	63	63	63	63	63	63	63
Avg low (°F)	45	45	45	45	44	44	44	44	44	44	44	43	43	43	43	43	42	42	42	42	42	42	42	42	42	42	42	42	42	42	42

	Avg high (°F)	Avg low (°F)
1	68	45
2	68	45
3	67	45
4	67	45
5	67	44
6	66	44
7	66	44
8	66	44
9	66	44
10	65	44
11	65	44
12	65	43
13	65	43
14	64	43
15	64	43
16	64	43
17	64	42
18	64	42
19	64	42
20	63	42
21	63	42
22	63	42
23	63	42
24	63	42
25	63	42
26	63	42
27	63	42
28	63	42
29	63	42
30	63	42
31	63	42

How December really feels in San Tan Valley

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F

heat index over the day's high

Days feeling ≤ 32°F

wind chill below the day's low

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

San Tan Valley weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 3rd-wettest month here — the current month is highlighted below.

Month	High / Low (°F)	Rainfall (inches)	Wet days	Daylight (hours)	Travel score
Jan	65° / 43°	1.5	4.2	10.1	7.2
Feb	69° / 46°	1.6	4.4	10.8	7.5
Mar	75° / 50°	1.1	3	11.7	8.4
Apr	83° / 56°	0.3	1.4	12.8	7.5
May	92° / 65°	0.2	0.7	13.7	4.4
Jun	101° / 74°	0.1	0.6	14.2	1.0
Jul	103° / 81°	0.8	3.8	14	0.3
Aug	101° / 80°	1.1	4.9	13.2	0.8
Sep	97° / 74°	1.0	3.2	12.2	2.5
Oct	87° / 62°	0.7	2.4	11.2	6.3
Nov	74° / 51°	0.7	2.5	10.3	8.5
Dec	65° / 43°	1.3	4.3	9.8	7.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 58% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 30%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	71	70	69	69	69	68	68	68	68
Cloudier (%)	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	30	31	31	31	32	32	32	32

	Clearer (%)	Cloudier (%)
1	71	29
2	71	29
3	71	29
4	71	29
5	71	29
6	71	29
7	71	29
8	71	29
9	71	29
10	71	29
11	71	29
12	71	29
13	71	29
14	71	29
15	71	29
16	71	29
17	71	29
18	71	29
19	71	29
20	71	29
21	71	29
22	71	29
23	71	29
24	70	30
25	69	31
26	69	31
27	69	31
28	68	32
29	68	32
30	68	32
31	68	32

Chance of precipitation in December

Any precipitation

San Tan Valley gets around 1.3 in of rain over 4.3 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 14% and peaks near 15% on the wettest days.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	11	12	12	12	13	13	13	13	13	13	13	13	14	14	14	14	14	14	14	14	14	14	14	14	15	15	15	15	15	15	15

	Rain chance (%)
1	11
2	12
3	12
4	12
5	13
6	13
7	13
8	13
9	13
10	13
11	13
12	13
13	14
14	14
15	14
16	14
17	14
18	14
19	14
20	14
21	14
22	14
23	14
24	14
25	15
26	15
27	15
28	15
29	15
30	15
31	15

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

Wind in December

Winds average 5 mph in December.

Across December, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (mph)	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	5	6
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (mph)	Feels
1	5	calm
2	5	calm
3	5	calm
4	5	calm
5	5	calm
6	5	calm
7	5	calm
8	5	calm
9	5	calm
10	5	calm
11	5	calm
12	5	calm
13	5	calm
14	5	calm
15	5	calm
16	5	calm
17	5	calm
18	5	calm
19	5	calm
20	5	calm
21	5	calm
22	5	calm
23	5	calm
24	5	calm
25	5	calm
26	5	calm
27	5	calm
28	5	calm
29	5	calm
30	5	calm
31	6	calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 hours at the start of December to 9 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:17 AM to 7:34 AM, and sunset from 5:15 PM to 5:24 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	10.0	9.9	9.9	9.9	9.9	9.9	9.9	9.9	9.9	9.9	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8	9.8
Sunrise (AM)	7:17	7:18	7:19	7:19	7:20	7:21	7:22	7:22	7:23	7:24	7:25	7:25	7:26	7:27	7:27	7:28	7:28	7:29	7:29	7:30	7:31	7:31	7:31	7:32	7:32	7:33	7:33	7:33	7:34	7:34	7:34
Sunset (PM)	5:15	5:15	5:15	5:15	5:15	5:15	5:15	5:15	5:15	5:15	5:15	5:16	5:16	5:16	5:16	5:17	5:17	5:17	5:18	5:18	5:19	5:19	5:20	5:20	5:21	5:21	5:22	5:22	5:23	5:24	5:24

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	10.0	7:17	5:15
2	9.9	7:18	5:15
3	9.9	7:19	5:15
4	9.9	7:19	5:15
5	9.9	7:20	5:15
6	9.9	7:21	5:15
7	9.9	7:22	5:15
8	9.9	7:22	5:15
9	9.9	7:23	5:15
10	9.9	7:24	5:15
11	9.8	7:25	5:15
12	9.8	7:25	5:16
13	9.8	7:26	5:16
14	9.8	7:27	5:16
15	9.8	7:27	5:16
16	9.8	7:28	5:17
17	9.8	7:28	5:17
18	9.8	7:29	5:17
19	9.8	7:29	5:18
20	9.8	7:30	5:18
21	9.8	7:31	5:19
22	9.8	7:31	5:19
23	9.8	7:31	5:20
24	9.8	7:32	5:20
25	9.8	7:32	5:21
26	9.8	7:33	5:21
27	9.8	7:33	5:22
28	9.8	7:33	5:22
29	9.8	7:34	5:23
30	9.8	7:34	5:24
31	9.8	7:34	5:24

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 3.19 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 3.19 kWh/m² to a high of 8.45 kWh/m² in June across the year — December's 3.19 kWh/m² sits near the bottom.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	3.4	3.3	3.3	3.3	3.3	3.2	3.2	3.2	3.2	3.2	3.2	3.2	3.2	3.1	3.1	3.1	3.1	3.1	3.1	3.1	3.1	3.2	3.2	3.2	3.2	3.2	3.2	3.2	3.2	3.2	3.2
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	3.4	Moderate
2	3.3	Moderate
3	3.3	Moderate
4	3.3	Moderate
5	3.3	Moderate
6	3.2	Moderate
7	3.2	Moderate
8	3.2	Moderate
9	3.2	Moderate
10	3.2	Moderate
11	3.2	Moderate
12	3.2	Moderate
13	3.2	Moderate
14	3.1	Moderate
15	3.1	Moderate
16	3.1	Moderate
17	3.1	Moderate
18	3.1	Moderate
19	3.1	Moderate
20	3.1	Moderate
21	3.1	Moderate
22	3.2	Moderate
23	3.2	Moderate
24	3.2	Moderate
25	3.2	Moderate
26	3.2	Moderate
27	3.2	Moderate
28	3.2	Moderate
29	3.2	Moderate
30	3.2	Moderate
31	3.2	Moderate

Planning a trip in December

Is December a good time to visit San Tan Valley?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.0

Sightseeing

6th-best month of the year

2.5

Beach & pool

12th-best month of the year

December is one of the better times to visit San Tan Valley for general sightseeing.

What to pack for San Tan Valley in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, San Tan Valley sees daytime highs around 65°F and nights near 43°F. Worth packing: a warm layer. About 4 days see rain.

a warm layer

UV index in San Tan Valley in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Tan Valley peaks around June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	4	5	5	7	9	11	11	11	9	6	4	3
Level	Moderate	Moderate	Moderate	Very high	Very high	Extreme	Extreme	Extreme	Very high	High	Moderate	Moderate

	UV index (midday)	Level
Jan	4	Moderate
Feb	5	Moderate
Mar	5	Moderate
Apr	7	Very high
May	9	Very high
Jun	11	Extreme
Jul	11	Extreme
Aug	11	Extreme
Sep	9	Very high
Oct	6	High
Nov	4	Moderate
Dec	3	Moderate

Air quality in San Tan Valley in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in San Tan Valley is worst in June — around 28 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 12 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	13	13	14	14	14	28	14	13	13	12	13	13
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	PM2.5 (µg/m³)	Level
Jan	13	Moderate
Feb	13	Moderate
Mar	14	Moderate
Apr	14	Moderate
May	14	Moderate
Jun	28	Moderate
Jul	14	Moderate
Aug	13	Moderate
Sep	13	Moderate
Oct	12	Moderate
Nov	13	Moderate
Dec	13	Moderate

Location & terrain

Where is San Tan Valley?

San Tan Valley sits at 33.2°N, 111.5°W, 1,516 ft above sea level, in United States. The nearest listed city is Queen Creek, 7.5 mi away.

Topography around San Tan Valley

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of San Tan Valley.

Within 2 miles, the terrain around San Tan Valley has only modest variations in elevation — a maximum elevation change of 92 ft around an average of 1,516 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,066 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 7,251 ft.

The land around San Tan Valley is covered by cropland (40%) and bare terrain (25%) within 2 miles, bare terrain (28%), grassland (27%) and shrubs (25%) within 10 miles, and shrubs (58%) within 50 miles.

2 miles

92 ft

cropland 40%

10 miles

1,066 ft

bare terrain 28%

50 miles

7,251 ft

shrubs 58%

treesshrubsgrasslandcroplandartificial surfacesbare terrainwater

← November San Tan Valley year-round climate January →Best places to visit in December

December weather nearby: Queen Creek 7.5 mi · Florence 14 mi · Apache Junction 16 mi · Gilbert 19 mi · Chandler 20 mi · Mesa 24 mi · Casa Grande 25 mi · Tempe 27 mi

United States travel facts

Power plugs: Type A / B; 120 V · 60 Hz
Prices: ≈ 100% of US; price level, 2025
GDP per capita: $90,027; 2025
Happiness: 6.8 / 10; World Happiness, 2025
Safe drinking water: 98%; of population, 2024
Homicide rate: 5.8; per 100k, 2023
Road deaths: 12.7; per 100k/yr, 2019
Income group: High; World Bank
Religion

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Tan Valley (33.1911°, -111.528°, elevation 1,516 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).

	Avg high (°F)	Avg low (°F)
1	68	45
2	68	45
3	67	45
4	67	45
5	67	44
6	66	44
7	66	44
8	66	44
9	66	44
10	65	44
11	65	44
12	65	43
13	65	43
14	64	43
15	64	43
16	64	43
17	64	42
18	64	42
19	64	42
20	63	42
21	63	42
22	63	42
23	63	42
24	63	42
25	63	42
26	63	42
27	63	42
28	63	42
29	63	42
30	63	42
31	63	42

	Clearer (%)	Cloudier (%)
1	71	29
2	71	29
3	71	29
4	71	29
5	71	29
6	71	29
7	71	29
8	71	29
9	71	29
10	71	29
11	71	29
12	71	29
13	71	29
14	71	29
15	71	29
16	71	29
17	71	29
18	71	29
19	71	29
20	71	29
21	71	29
22	71	29
23	71	29
24	70	30
25	69	31
26	69	31
27	69	31
28	68	32
29	68	32
30	68	32
31	68	32

	Rain chance (%)
1	11
2	12
3	12
4	12
5	13
6	13
7	13
8	13
9	13
10	13
11	13
12	13
13	14
14	14
15	14
16	14
17	14
18	14
19	14
20	14
21	14
22	14
23	14
24	14
25	15
26	15
27	15
28	15
29	15
30	15
31	15

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°F)	Avg low (°F)
1	68	45
2	68	45
3	67	45
4	67	45
5	67	44
6	66	44
7	66	44
8	66	44
9	66	44
10	65	44
11	65	44
12	65	43
13	65	43
14	64	43
15	64	43
16	64	43
17	64	42
18	64	42
19	64	42
20	63	42
21	63	42
22	63	42
23	63	42
24	63	42
25	63	42
26	63	42
27	63	42
28	63	42
29	63	42
30	63	42
31	63	42

	Clearer (%)	Cloudier (%)
1	71	29
2	71	29
3	71	29
4	71	29
5	71	29
6	71	29
7	71	29
8	71	29
9	71	29
10	71	29
11	71	29
12	71	29
13	71	29
14	71	29
15	71	29
16	71	29
17	71	29
18	71	29
19	71	29
20	71	29
21	71	29
22	71	29
23	71	29
24	70	30
25	69	31
26	69	31
27	69	31
28	68	32
29	68	32
30	68	32
31	68	32

	Rain chance (%)
1	11
2	12
3	12
4	12
5	13
6	13
7	13
8	13
9	13
10	13
11	13
12	13
13	14
14	14
15	14
16	14
17	14
18	14
19	14
20	14
21	14
22	14
23	14
24	14
25	15
26	15
27	15
28	15
29	15
30	15
31	15

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°F)	Avg low (°F)
1	68	45
2	68	45
3	67	45
4	67	45
5	67	44
6	66	44
7	66	44
8	66	44
9	66	44
10	65	44
11	65	44
12	65	43
13	65	43
14	64	43
15	64	43
16	64	43
17	64	42
18	64	42
19	64	42
20	63	42
21	63	42
22	63	42
23	63	42
24	63	42
25	63	42
26	63	42
27	63	42
28	63	42
29	63	42
30	63	42
31	63	42

	Clearer (%)	Cloudier (%)
1	71	29
2	71	29
3	71	29
4	71	29
5	71	29
6	71	29
7	71	29
8	71	29
9	71	29
10	71	29
11	71	29
12	71	29
13	71	29
14	71	29
15	71	29
16	71	29
17	71	29
18	71	29
19	71	29
20	71	29
21	71	29
22	71	29
23	71	29
24	70	30
25	69	31
26	69	31
27	69	31
28	68	32
29	68	32
30	68	32
31	68	32

	Rain chance (%)
1	11
2	12
3	12
4	12
5	13
6	13
7	13
8	13
9	13
10	13
11	13
12	13
13	14
14	14
15	14
16	14
17	14
18	14
19	14
20	14
21	14
22	14
23	14
24	14
25	15
26	15
27	15
28	15
29	15
30	15
31	15

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100